A so-called Cooperative Multiple-Input Multiple-Output (Co-MIMO) technology has been considered as a key physical layer technology in International Mobile Telecommunications-Advanced (IMT-Advanced) standard. In a global scale frequency multiplexing cellular system, inter-cell interference has become a main factor that may limit the performance of mobile communications. A basic concept of the Co-MIMO is to coordinate signal transmission of multiple base stations, so as to reduce the inter-cell interference. In a Co-MIMO system, multiple base stations cooperatively provide a communication service for multiple user terminals (i.e. mobile stations) at the same time.
In a Co-MIMO system, when a base station sends data to multiple user terminals, a multi-user interference (MUI) may be generated. Meanwhile, when a user terminal receives data sent by multiple base stations, an inter-cell interference may be generated. Though the current Co-MIMO system may reduce the inter-cell interference to some extent in a conventional precoding manner based on a codebook, solutions for reducing the MUI have not been provided.